Growth in the livestock and dairy industries has made it necessary to process increasingly large quantities of animal wastes, which cause nasty and offensive odors resulting in enviromental pollution. The offensive odors and other environmental pollution generated in barns also face practical limitations on where dairy and livestock farms can be located, since urine emits especially offensive odors and contaminates water systems. The farming industry incurs large operating costs in treating such waste on account of the large-scale facilities and complicated processing involved. Moreover, it takes a fairly long time to reduce the offensive odors caused by urine to a tolerable level.
Wastes or excretions from domestic animals, such as diary cattle, beef cattle, swine, sheep and the like, contain organic materials, when properly treated, that can benefitably be reutilized for agricultural purposes. Wastes from domestic animals have traditionally been turned into compost and used as a fertilizer, but composting requires much time and labor. Many effective techniques have been developed to reuse solid wastes for fertilizer and compost.
In traditional composting, solid wastes, after adjusting their water content, are cured in air for an extended period with periodic stirring. At that time, microorganisms in soil decompose this mixture into humus, thus transforming it into compost. This natural process has detrimental drawbacks, such as requiring a long curing time and much labor. Another disadvantage is the difficulty in securing a physically and chemically stable product. Given limitations in the availability of labor, large-scale facilities and lands, traditional composting can not be applied for today's large-scale livestock and dairy farms, where large quantities of wastes are excreted day-by-day.
Among various forms of animal wastes, urine is the most difficult to treat due to its high ammonia content. In fact, an effective means for treating urine has never been developed until now.
The inventors of the present application have studied recycling methods for treating urine and other liquid wastes more efficiently with suppressing the emission of nasty and offensive odors to convert them to a material that can be reused for various agricultural purposes.
First of all, the present invention is turned its attention to the characteristics of soil. Soil is a source of sustenance for plant and animal lifes, and absorbs the remains of plants and animals after they die. Wastes excreted from animals and plants, their remains, and other organic materials eventually are decomposed into inorganic compounds and synthesize humus. The problems such as puterfaction and offensive odors do not occur during the decomposition in soil. Soil that contains a large quantity of humus is generally capable of yielding large crops without the use of additional fertilizers. Moreover, humus makes toxic metallic ions and nonmetallic substances harmless, and helps to preserve the natural ecological balance while preventing the proliferation of harmful insects.
In accordance with the present invention, considering how soil breaks down organic wastes, a new method for treating wastes has been developed in a manner facilitated by incorporating this natural process.
Organic materials in soil synthesize humus in the processes of chemical reactions, in which processes soil microorganisms play a vital role. FIG. 1 shows the mechanism of producing humus. In one of the chemical reactions, microorganisms decompose organic materials into water and inorganic substances, thereby reducing their molecular weights. The resultant products of this decomposing reaction are useless substances and further generates the offensive odors usually associated with ammonia and methane. The products are also incapable of preventing the proliferation of harmful bacteria and insects.
On the other hand, soil organics can be composed of carbohydrates, lignin, and proteins from organic substances. Microorganisms consume carbohydrates and lignin as a source of energy, and in turn secrete phenolic compounds and other metabolic by-products. Soil microorganisms also obtain nutrition by decomposing proteins into amino acids and peptides. Humus is eventually synthesized through these chemical reactions.
Humus--which consists of humin, humic acid, and fulvenic acid--has a natural purification function. The purification process quickly changes animal and plant wastes into soil humus and high-quality water, thus resulting to control the growth of miscellaneous bacteria, to prevent the decay thereof, and to eliminate offensive odors. Minerals and water exhibit essential function for promoting the metabolic activities of the microorganisms in soil to accelerate the production of humus. The inorganic substances in soil consist mainly of the clay and minerals found in the particular area. These minerals serve as an activator for the microorganisms' metabolism. Moreover, water in soil differs in composition from ordinary "pure" water by extensively dissolving various mineral particles. The water in soil has a favorable effect on crops and microorganisms.
In summary, minerals and water having minerals dissolved therein are the essential materials for promoting the metabolic activities of soil microorganisms and producing humus from organic substances in the soil. The earth's ecosystems have been maintained over 3.5 billion years by the vital participation of microorganisms.
Laid-Open-Publication of Japanese Patent Application No. 4-238887 discloses a method for producing highly cured compost on an industrial scale. According to the prior art, the compost is produced from solid organic wastes, such as animal wastes, as the starting material. In the method disclosed therein, to accelerate the production of humus, a substance for activating soil microorganisms is added to solid wastes (mainly excrement) from domestic animals. Specifically, water content in solid wastes as the starting material is controlled to 60%-70%. Then, seed compost and silicate particles derived from andesite or rhyolite are added to activate the metabolic functions of the soil microorganisms, specifically in the form of facultative anaerobes, or a mixture of facultative anaerobes and aerobic bacteria. In short, the starting material is mixed uniformly with agents that promote humus production. The mixture is stirred periodically during the curing period. By so processing, well-cured compost is obtained in a very short period of time.
Further, Laied-Open-Publication of Japanese Patent Application No. 4-265286 discloses a method for converting the well-cured compost produced as described above into liquid form. That is, the well-cured compost, which is rich in soil microorganisms, is dissolved in water in the presence of granite, rhyolite, or basalt as an active ingredient. The mixture is then aerated to activate the microorganisms, obtained the obtained mixture thereby obtained being an aqueous solution concentrated with soil microorganisms and their metabolic by-products. The aqueous solution is then extracted from the mixture by the filtration to remove solid components, thus obtaining a liquid compost which can be applied together with solid compost to farmlands or other greenery areas and may be used as a seed compost for the source of bacteria of materials to be composted.